Clinical and pathologic materials of various types of retinal dysfunctions will be collected and analyzed. The late effects of radiant energy on the retina will be studied. A Rhesus monkey whose macula was damaged three or four years ago by argon laser or by the light of an indirect ophthalmoscope will be sacrificed and the retina will be examined by light and electron microscopy. Furthermore, experimental model of macular edema in rhesus monkey will also be studied by light and electron microscopy. Various retinal degeneration induced by vascular occlusion will be investigated. BIBLIOGRAPHIC REFERENCES: Torczinski, E., and Tso, Mark: The Architecture of the Choriocapillaris at the posterior pole. Amer. J. Ophthal., 81: 428, 1976. Rao, N.A., and Tso, M.O.M.: Chalcosis in the Human Eye, Arch. Ophthal., 94: 1379, 1976.